Could eyes hold the key to understanding Alzheimer’s?

At the University of Lancashire, new tests have been carried out in an attempt to better understand Alzheimer’s disease. Alzheimer’s disease is the most common type of dementia which affects around 496,000 people in the UK and can be characterised by memory loss, mood changes and problems with communication and reasoning. Whilst not exclusively limited to old age, dementia affects around one in fourteen people over the age of 65 and one in six over the age of 80. Some of the causes are believed to be the lack of certain chemicals in the brain and protein ‘tangles’ forming in the brain which causes the death of brain cells.

The University of Lancashire teamed up with the Lancashire Teaching Hospital’s NHS Foundation Trust to carry out an in-depth experiment with patients suffering from Alzheimer’s. The study included 18 Alzheimer’s patients, 25 sufferers of Parkinson’s disease, 17 healthy young people and 18 healthy older people. They were asked to track the movement of lights on a computer screen and their responses were measured. In some cases, the participants were asked to look away from the screen. Ordinarily, studies on Alzheimer’s patients involve neuropsychological tests but these have proved difficult to complete as the patients become confused and frustrated. However, over the last decade, researchers have been developing new ways to explore the workings of the brain and have developed eye-tracking as an alternative approach. By closely studying the way the brain controls the movements of the eye, researchers were able to investigate the patients’ cognitive abilities such as memory, attention and cognitive inhibition.

The results were very revealing: detailed eye-tracking measurements showed that Alzheimer’s patients made numerous errors when asked to look away from the light, errors which were 10 times more frequent than in the healthy participants. They also found it particularly difficult to notice and amend the errors made. Among these patients who made errors, the researchers measured memory function and discovered a correlation. It appeared that there is a link between poor memory skills and cognitive skills.

Dr. Trevor Crawford of the department of Psychology at the university suggested that these results were very important because they demonstrated, for the first time, a connection with memory difficulties in Alzheimer’s patients. The patients’ difficulties in noticing and correcting the errors made on the eye-tracking test may be linked to problems with the memory networks in the brain.

Researchers are excited by the possibility that these simple, minimally invasive tests could lead to earlier diagnosis of the disease.

Victoria writes for one of the leading online suppliers of round spectacles, Direct Sight.